554
Op doesn't have time for interviews
(programming.dev)
Post:
You have three switches in one room and a single light bulb in another room. You are allowed to visit the room with the light bulb only once. How do you figure out which switch controls the bulb? Write your answer in the comments before looking at other answers.
Comment:
If this were an interview question, the correct response would be "Do you have any relevant questions for me? Because have a long list of things that more deserving of my precious time than to think about this!
Yeah, after reading the answers I see it more clearly. Also, I assume in hindsight that it's three switches which can be on or off, so we know if all three are off the light is off. Which helps as well.